C-54 Skymaster transport

The C-54 Skymaster began as a militarized DC-4 in the early 1940s. It was a transport aircraft that remains in limited civil use.

To create the DC-4A, Douglas and five U.S. airlines studied the success of the twin-engined DC-3 and created a larger airliner capable of transcontinental flight (the DC-4E, a more venturesome, triple-tailed pressurized airliner, was a flop that later reappeared as a Japanese bomber design). Even in 1942 the DC-4/C-54 design was not radical: a low-wing,...